And in a stunning display of stupidity, the Pentagon is letting the USAF run the competition, which considering their record the past two times, is a lot like giving Jack the Ripper the straight razor concession at the prostitutes convention.
Boeing has wised up, and had decided to titch the “Frankentanker”, (paid subscription required) which had the “767-200 airframe; over-wing exits from the 767-300; floors, doors and structurally enhanced wings from the 767-300F; and a cockpit, tail section (with a more capable auxiliary power unit) and flaps from the 767-400ER,” which is a good thing.
Interestingly enough, they are also making noises about using the 777, but that aircraft appears to be rather too large for the requirements as I understand them unless they take the sawzall to it, and shorten the fuselage by a lot.
The most significant change here is that the specifications are much more explicit, because the challenge was driven by the wiggle room the last time around. (see graph pr0n, and click for full size)